Typical dual spool retractors are well known in the patent art as shown in the U.S. Pat. Nos. 4,065,070 issued to Regis Pilarski and Gerald Yates and 4,164,336 issued to Wallace Higbee and Robert Rumpf. The retractor spools are spring loaded to apply a return bias constantly seeking to return all loose webbing in the belt to the spool. Comfort mechanisms having means for preventing rewind of a belt are also well known in the retractor art as, for example, the U.S. Pat. Nos. 4,002,311; 4,034,931 and 4,149,683 to Robert C. Fisher and Cecil A. Collins. In such mechanisms, the seat belt user can select a point in the protraction of webbing or belt to prevent the rewind spring from acting on the belt while the belt is in a selected use position. In such comfort mechanisms, withdrawal of the belt from the spool is not impaired so that the occupant can lean forward to adjust his seating position or to reach vehicle controls. However, such comfort mechanisms are known to prevent the rewinding of the belts when otherwise desired; for example, when the seat belt is unbuckled to permit egress of the seat occupant from the vehicle.
Accordingly, U.S. Pat. No. 3,973,786 issued to Lloyd W. Rogers, Jr. provides a device which is responsive to movement of the vehicle door from the closed to the open position as the occupant leaves the vehicle to disengage the comfort mechanism so that the spring may rewind the belt upon the retractor spool.
The Higbee and Kuntzman U.S. Pat. No. 4,307,853 illustrates a dual spool retractor having a rack and pinion mechanism driven by a first spool to allow retraction of a second spool after a predetermined amount of retraction occurs in the first spool driving the rack and pinion. The first spool includes a pinion gear that drives the rack through a gear train. The second spool whose retraction is prevented includes a comfort mechanism with a spring finger that is released by a cam surface on the rack to allow retraction of the second spool after the predetermined amount of retraction of the first spool has occurred. The cam surface on the rack releases the spring finger during belt retraction only.
The Ocker et al U.S. Pat. No. 4,343,445 employs a different mechanism to release the comfort mechanism after a predetermined number of retraction revolutions of one spool. The release mechanism of this patent employs a pivotable release lever to disengage the spring finger of the comfort mechanism and a rotatable cam rotating with the one spool to actuate the release lever. The one spool includes a spur gear driving an idler gear which in turn drives a ring gear on which the cam is carried. The Fox U.S. Pat. No. 4,337,907 includes a similar release mechanism to this same end.
A dual spool retractor of a type different from those of the preceding patents is described in the Stephenson U.S. Pat. No. 4,303,209. The dual spool retractor of this patent includes axially aligned dual spools and a comfort mechanism for reducing retraction force acting on the torso belt.
As explained in an article entitled "Seat-Belt Slack: Comfort Device In U.S. Car Raises Safety Concern" published in The Wall Street Journal, July 31, 1987, automobile seat belt systems having a comfort mechanism that allows the user to provide one or more levels of slack (or reduced tension) in the shoulder belt have been criticized as allowing the user, either intentionally or inadvertently, to provide excessive slack in the shoulder belt that impairs the protectiveness of the belt in the event of a crash.
Excessive slack in the shoulder belt can be provided by the user simply by extending or protracting the shoulder belt relative to the lap belt to various extents that actuate the comfort mechanism. The user can actuate the comfort mechanism inadvertently by leaning forward to adjust controls on the dashboard or to pick up an article from the floor.